Telephone system



March 9, 1937. s. B. WILLIAMS TELEPHONE SYSTEM Filed April 18, 1935 lNl ENTOR B 5. B. W/LLIAMS A T TORNEV Patented Mar. 9, 1937 UNITED a;

rA'rENT OFFICE TELEPHONE SYSTEM Application April 18, 1935, Serial No. 16,946

1'7 Claims.

This invention relates to telephone systems and particularly to those having coin controlled substations.

The objects of the invention are to eliminate 5 the use of complicated and expensive devices for the collection of coins; to obviate the necessity of round and battery connections at the substation; and to otherwise effect improvements in coin controlled equipment.

It has been the practice heretofore to control the disposition of a coin deposited by a calling party by the use of a polarized magnet, which is usually connected to ground at the substation, the operating circuit including either one or both of the line conductors and employing the ground for the return path. It is also old in coin lines of this kind to equip the substation with a dial for controlling the central oflice switches over an impulse circuit including both line conductors in series.

A feature of the present invention is to improve these prior arrangements by providing a coin substation that is free from all ground or battery connections for dialing and for coin control, and in which an ordinary electrcmagnet is used for collecting the coin automatically when the called party answers. This is accomplished by a novel circuit arrangement in which a rectifier is inserted in series with the coin magnet, both magnet and rectifier being connected across the line conductors in response to the deposit of the coin.

Another feature is an arrangement in which the calling party may recover the deposited coin, any time before the called subscriber answers, by replacing his receiver and manipulating a return button. This button is held ineffective so long as the receiver is off the hook to prevent the calling party from securing the wanted number and also recovering his coin.

Another feature is a coin control substation for dial systems in which it is necessary for the patron to deposit a coin before the dial is rendered effective on all calls for which a charge may be made, and in which the dial is so constructed and related to the coin mechanism that the dial contacts are rendered effective to transmit impulses Without the deposit of a coin when the dial is positioned to transmit impulses reprerenting a designation for which no charge is necessary. Other features of the invention will be explaine more fully in the following detailed description and will also be more fully understood from the claims appended hereto. The description should be considered in connection with theaccompanying drawing.

Referring to the drawing, Fig. 1 shows, in diagrammatic form, a. coin' subscriber station-A and line I, a line-finder LF having access to the line I, a selector switch S, a connector switch C and a called subscriber station SUB. This substation A requires the deposit of a coin when making free calls.

Fig. 2 shows, in diagrammatic form, a coin subscriber station B and a line I I0. Thissubstation B does not require the deposit of a coin when making free calls.

Fig. 3 shows, in diagrammatic form, the construction of a dial suitable for use at substation B in Fig. 2. I

Substation A, in addition to the usual dial, receiver and transmitter, comprises a coin mechanism consisting of contact springs 30, a coin chute 3 I, a coin trigger 32, a coin trigger lever-33, a coin trap 34, a reset lever 31, a reset plate 4|, a non-polarized coin magnet '35, a copper oxide rectifier 48, and anon-polarized relay 50 which has its armature 5| associated with a lever 55 and push button 54 to control the refunding of the deposited coin 51.

Referring to Fig. 1, let us assume'that a sub scriber at the calling substation A removes the re ceiver 23 from the switchhook 19 to make a call for which prepayment is required. When the receiver 23 is removed from the switchhook 19 a metallic loop circuit will be closed through substation A from terminal 2, over line I, conductor 6, conductor 8, pulsing springs l and II of the dial, conductor I5, transmitter l6, conductor l1, conductor l8, the left contacts of switchhook l9, the left winding of induction coil 20, conductor 2!, non-polarized relay conductor 1, line I, terminal 3. A receiving circuit will be closed from conductor 6, through condenser 22, the right winding of induction coil 20, the right contacts of switchhook l9, receiver 23, conductor 24, contact springs 13 and M of the dial to conductor l8.

The brushes 4 and 5 of the line-finder LF will connect with the terminals 2 and 3, in a manner well known to the art, and extend the metallic loop circuit of substation A described above through to a selector switch S. The selector switch S will function to send dial tone to the calling substation A and to place negative battery on conductor 1 and ground on conductor 6 of the metallic loop circuit of substation A in a. manner well known to the art.

Under these circumstances dial tone will be heard in therreceiver 23 of substation A and magnet 50 will operate over the metallic loop circuit which has been established through substation A and the selector switch S. The magnet 50 will operate its associated armature 5| which will op erate and lock lever 55 in such a position that it will not engage the coin trap 34 when the push button 54, which is set in the frame 53 of substation A, is depressed. If no coin has been deposited at the calling substation A, the contact springs 30 of the coin mechanism of substation A will not operate, and a short circuit will be maintained around the pulsing springs H) and of the dial through conductors l 5 and 43, the back contact of contact springs 30 and conductors 45 and 8. This prevents dialing from the calling substation A until a coin is deposited in coin chute 3| of the coin mechanism.

If on or before receiving the dial tone, the calling party deposits a coin 5? in the coin chute 3|, the coin 51 will pass through the coin chute 3| to the coin trap '34 thereby operating the coin trigger 32 which in turn will allow the coin trigger lever 33 to operate. Operation of the coin trigger lever will cause the contact springs 3&3 to

function closing the upper and the lower front contacts and opening the back contact of said contact springs 33. Closure of the upper front contact will place a short circuit around the transmitter I6 through leads 43 and 44. Closure of the lower front contact willclose a circuit from conductor 8 through conductors 45 and 45, the non-polarized coin magnet 35, copper oxide rectifier 48, conductor 49 to conductor 7 in parallel with. the previously described metallic loop circuit through non-polarized relay 50 and transmitter IS. The. copper oxide rectifier 48 is a unipolaritydevice which will not permit current to pass through in the direction opposite to that indicated by the symbolic arrowhead, therefore, coin magnet 35 will not operate. Opening of the back contacts of contact springs 30 will remove the short circuitfrom around the pulsing springs I0 and of the dial thereby permitting the call-' ing party to dial a number. The dial is then operated and released in the usual manner causing the selector switch S and the. connector switch C to function in a manner well known to the art. During the dialing operation, contact springs |2 and I3 of the dial are closed, thereby short-circuiting the transmitter l6, and contact springs l3 and M of the dial are opened, thereby opening the circuit through the receiver 23.

The called subscriber at substation SUB is signalled in any desired manner and when the receiver at substation SUB is removed from the switchhook a circuitis closed from negative battery through the upper winding of relay 6%), conductors 6| and 62 through brush 63,- terminal t4 through the subscribers loop at substation SUB, terminal 65, brush 66, conductors 67 and 68 to ground throughthe lower winding of relay 60 thereby operating relay 69. Operation of relay 6!! will reverse the direction of the current flow in the metallic loop circuit of substation A described before which is in series with the windings of the impulse relay 69 by transferring the negative battery supply from the lower back contact to the lower front contact of relay 5i) and by transferring the ground supply from the upper back contact to the upper front contact of relay 68. The directionof the current flow being reversed through conductor 49, copper oxide rectifier 48, conductor 4?, coin magnet 35 which has low resistance in comparison with non-polarized relay 50, conductor 46, the lower front contact of contact springs 30, and conductors 45 and 8.

The copper oxide rectifier 48 will permit current to pass through this circuit under this condition and the coin magnet 35 will operate. Operation of the coin magnet 35 will operate the coin trap 34 and the coin 5? will drop onto plate 4| and thence into the coin hopper as indicated by the arrows 39 and 49. The weight of the coin 5'! as it falls onplate 4| will cause said plate 4| to pivot about fulcrum 42 and operate reset lever 37 which pivots about fulcrum 38 and resets the coin trap 34, the coin trigger lever 33, the coin trigger 37 and the contact springs 30.

With the functioning of the contact springs 3|], the upper and the lower front contacts will open and the back contact will close. Opening of the upper front contact will remove the short circuit from around the transmitter l6 and opening of the lower front contact will open the circuit through the copper oxide rectifier 48 and the coin magnet 35 thus removing the bridge from the line and permitting coin magnet 35 to release. The calling party may then talk to the called subscriber in the usual manner.

If it is desired to abandon the call at the substation A because the line of the called subscriber SUB is busy or because the called subscriber SUB does not answer, the receiver 23 at substation A is replaced on the switchhook I4. This opens both of the contacts of switchhook H) in the metallic loop circuit at substation A, thereby permitting magnet 56 to release and release its associated armature 5| which is restored by spring 52. This will allow the lever 55 to be moved to such a position so that when push button 54 is depressed, the 1ever55 will engage the coin trap 34 and tilt it so that the coin 5'! will be dropped in the direction indicated by the arrow 55 and will be returned to the calling subscriber at substation A.

Let us assume that the calling substation A desires to obtain a connection with a free line, such, for example, as the zero operator. In this event the receiver 23 at substation A is removed from the switchhook 23 and a coin 5'5 is deposited in the coin chute 3| of the coin mechanism, which will function as outlined above for an ordinary call and close the metallic circuit through to the selector switch S. The dial at substation A is operated and released in accordance with the code number of the zero operator, which is usually 0. The selector switch S will accordingly be set in accordance with its primary movement upon the proper trunk level which we will assume to be the 10th or 0 trunk level of the switch. The

selector switch will function in the usual manner and extend the comiection to the zero operator displaying a signal at her position as an indication that a call is in waiting. When the call is answered by the zero operator there is no current reversal in the calling line loop, thus preventing the operation of the coin magnet The zero operator will hold the established connection to the calling subscriber with her cord and will advise him to place the receiver 23 on the switchhook I9 and then depress push button 54 to obtain a refund of the deposited coin 5?. As the receiver 23 is replaced on the switchhook 9 the contacts of the switchhook I8 are opened thereby opening the circuit through magnet 55 which will release and allow the coin to be returned as outlined above for an abandoned call. The calling subscriber may then take the receiver 23 from the switchhook l9 and tall: to the desired party in the usual manner.

Referring to Fig. 2, the substation B, in addition to the ordinary transmitter, receiver .and coin mechanism as described heretofore under the description of substation A in Fig. l, is equipped with a dial arranged to permit the calling substation B to complete a free call without depositing a coin in the coin mechanism. This dial is shown diagrammatically in Fig. 3 and functions in the following manner. The outward appearance of the dial is similar to that of any other standard dial, and it has a finger wheel 84, a number plate 85 and a finger stop 86. The

interior of the dial has a special construction and consists of contact springs I0 to 11 inclusive, a cam I8 which rotates in unison with the finger wheel 84, a lever arm I9 which has a roller 80 conveniently attached at one end and which joins springs I2 and TI so that any movement of lever arm ":9 is transmitted to springs I2 and Ti, a collar BI having an inner surface 82 and .an outer surface 83, a pulse pawl 81, a pulse pawl spring I43 and a pulse wheel 89.

When the finger wheel 84 is moved from its normal position the cam I8 moves in a clockwise direction and permits springs I3 and I4 to make contact and springs I5 and I6 to break contact. As soon as the finger wheel 84 is moved in a clockwise direction, roller 80 on lever arm I9 will contact with the surface 82 of collar 8I and move lever arm I9 in such a manner as to keep springs I5 and I? from breaking contact and springs I2 and I4 from making contact in all positions of the dial except the position it assumes when fully rotated preparatory to sending the digit 0 When the dial has reached its full forward position for the digit 0, the roller 80 will drop from surface 82 of collar BI and permit spring I2 to make contact with spring I4 and establish a common contact with spring I3. Spring I! will break contact with spring I5. When the finger wheel 84 is released the roller 80 on lever arm I9 will contact with surface 83 of collar 8| in such a manner as to hold springs I2, I3 and I4 in common contact, and springs I5 and 11 open until the finger wheel 84 has restored to its normal position where the lever arm I9 again assumes its normal position as shown in Fig. 3. The pulsing springs I0 and 'II are operated in the usual manner by pulse pawl 81 which is pivoted at 88 and actuated under control of the pulse wheel 89 and the pulse pawl spring I43.

Referring to the circuit shown in Fig. 2, let us assume that a subscriber at the calling substation B desires to complete a call to a party where prepayment is required. The receiver 91 at substation B is removed from the switchhook 98 thereby allowing the contacts of switchhook 98 to close. Closure of the left contact of switchhook 90 will close a metallic loop circuit from terminal I40, line IIO, conductors 90 and 92, the back contact of contact springs I00, conductor 93, transmitter 94, conductor 95, contact springs TI and I5 of the dial, conductor I03, the left contact of switchhook 98, the left winding of induction coil 99, conductor I42, non-polarized relay I33, conductor 9I, line III! to terminal I4I. Closure of the ring contact of switchhook 98 will close a receiving circuit in parallel with the circuit through the transmitter 94 from conductor 98, through condenser IOI, the right winding of induction coil 99, the right contact of switchhook 98, receiver 91, conductor 90, contacts I0 and T5 of the dial to conductor I03. The line-finder LF will function and extend the metallic loop circuit of substation B through to a selector switch S which will function to send dial tone to the calling substation B and to place negative battery on terminal MI and ground on terminal I40 in a manner well known to the art. Dial tone will be heard in the receiver 91 at substation B and magnet I33 will operate over the metallic loop circuits described above; Operation of magnet I33 will cause the associated coin refund mechanism to function in the manner described in Fig. 1. As outlined above in the description of the dial used in substation B, contact springs'IZ and I4 will not make contact and contacts I5 and TI will not breakcontact while any number other than 0" is being dialed. v The pulsing circuit through the pulsing contacts I0 and 'II of the dial will not be closed therefore for any call other than 0 until a coin is deposited in the coin chute I20 to operate the contact springs I00 and close the front contact of said contact springs I00.

If on or before hearing dial tone in the receiver 91 the calling subscriber places a coin in the coin chute I20, the coin mechanism will function as outlined herein for a prepayment call using substation A in Fig. 1. Closure. of the front contact of contact springs I00 will close the pulsing circuit from pulsing spring I0 of the dial, to conductors I02 and I03, the left contact of switchhook 98, the left winding of induction coil 99, conductor I42, relay I33, conductor 9I, line IIO, terminal I4I, line-finder LF, selector switch S, back through terminal I40, line IIO, conductors 90 and 92, front contact of contact springs I00, conductors H5 and I06, contact springs I4 and I3 of the'dial, conductors I05 and I04 to pulsing spring II of the dial. It will be noted that contact springs I3 and I4 will be closed only when the dial is out of the normal position and contacts I4 and. I2 will be closed only while the digit 0 has been dialed. In order to keep the metallic loop circuit closed so as to hold the selectorswitch S and the connector switch C in the positions they assume after a digit is dialed, a bridging circuit consisting of conductor III, copper oxide rectifier II2, conductor l I3, resistance H4, and conductor H6 is placed from conductor I I5 to conductor I04 which extends to the pulsing contact 'II of the dial. The copper oxide rectifier H2 is a uni-polarity device which will pass current only in the direction indicated by its symbolical arrowhead symbol and will now pass current through. Also, closure of the front contact of contact springs I00 will close a circuit through conductor II5, coin magnet I29, conductor I09, copper oxide rectifier I08 to conductor I04 in parallel with the previously described circuit through copper oxide rectifier H2 and resistance II4. Since copper oxide rectifier I08 is a uni-polarity device and is poled opposite to copper oxide rectifier II2, it will not pass collect the coin. Opening of the back contact of contact springs I00 will open the circuit through transmitter 94. The desired number may then be dialed and the called party signalled in the usual manner.

When the called party SUB answers, the polarity of the battery is reversed in the metallic loop circuit of Fig. 2. This causes a reversal of current fiow to the copper oxide rectifier I08 which will now pass through from conductor I04 to conductor I09 and thence to coin magnet I29 and conductor II5. Coin magnet I29 will operate and cause collection of the coin I30 and a resetting of the coin mechanism in the same manner as outlined herein for substation A in springs 15 and 16 are opened.

Fig. 1.

If the calling party at substation B desires to obtain refund of the coin before the called party answers he replaces the receiver 9! on the switchhook 98 and the circuit will function as outlined above for refund of a coin at substation A of Fig. 1.

Referring to the circuit shown in Fig. 2, a call may be made from substation B to an operator without depositing a coin. When a subscriber at the calling substation B desires to originate a call for which no charge is to be made and removes the receiver 34 from the switchhook 35, the metallic loop circuit is established as outlined for a prepayment call and the selector switch S will function to send dial tone to the calling substation B and to place battery and ground through the metallic loop circuit of substation B in a manner well-known to the art. After dial tone is heard the dial is operated to the or operator position and then released. As the dial is moved from the normal position, springs 13 and 74 of the dial are closed and Springs 12 of the dial will not make contact with spring 14 thus keeping the pulsing circuit open and spring 11 will not break contact from spring 15 thus keeping the transmitter circuit closed until the dial has been fully operated to the 0 position when said springs will operate and remain locked in their operated positions thus closing the pulsing circuit and opening the transmitter circuit to prevent pulsing through the transmitter 94 until the dial has restored to normal. Opening of contact springs 71, 16 and 15 will open the circuits through the receiver 91 and the transmitter 94. Closure of contact springs 12 and 14 will complete a metallic pulsing circuit through conductor 9|, magnetl33, conductor I42, the left winding of the induction coil 99, the left contact of switchhook 98, conductor I02, pulsing contacts 18 and II of the dial conductor I04, contact springs 73, T4 and 12 of the dial, conductors H31, 92 and 90. Magnet I33 operates over the metallic loop circuit as outlined before but performs no useful function at this time as there is no coin deposited. The dial pulses will be sent out and the operator will be obtained in a manner well known to the art. The subscriber at substation B will give the desired number to the operator who will complete the call in the manner described herein for a free call from substation A of Fig. 1.

Although many details of the coin mechanism have been omitted in the disclosure it is obvious that these may be supplied in accordance with the known structures of the prior art. For example the coin box may be of the multi-slot type with the usual tone mechanism for apprising the operator of the coins deposited for the payment of toll calls that she may complete.

That is claimed is:

l. In a telephone system, a telephone line and a substation therefor, an impulse circuit including the conductors of said line in series, a transmitter for producing impulses in said circuit, a coin disposal mechanism at said substation, a non-polarized coin disposal magnet for actuating said mechanism to dispose of a deposited coin, and a circuit for energizing said magnet including the conductors of said line in series.

2. Ina telephone system, a line having a sub- 75 station thereon,an impulse circuit including the conductors of said line in series, a transmitter for producing impulses in said circuit, a coin mechanism and a non-polarized magnet at said substation, an operating circuit for said magnet including the conductors of said line in series, and means for operating said magnet over said circuit when the called party answers.

3. In a telephone system, a telephone line and a substation therefor, a coin mechanism at said substation, a non-polarized magnet at said substation for actuating said mechanism to dispose of a deposited coin, a circuit for said magnet including the conductors of said line in series, a source of current connected to said circuit, a rectifier connected in circuit with said magnet in such a direction as to oppose the flow of current through the magnet, and means for reversing the direction of current flow to operate. said magnet to dispose of a deposited coin.

4. In a telephone. system, a line and a substation therefor, a non-polarized magnet and a rectifier at said substation, a source of current connected to said line, coin operated mechanism at the substation for connecting said magnet and rectifier in a circuit including the conductors of said line in series and in such a manner that the rectifier opposes the flow of current from said 'source through said magnet, means responsive to the answer of a called party for reversing the direction of current flow to cause the operation of said magnet, and means controlled by the operation of the magnet for disconnecting the magnet and rectifier from the line.

5. In a telephone system, a telephone line and a substation therefor, a receiver and mechanism for the disposition of a coin at said substation, a coin magnet and a rectifier, a source of current, means controlled by a deposited coin for connecting said magnet and rectifier in circuit with said source, means for reversing the flow of current from said source when the called party answers for operating the magnet to collect the coin, means controlled by the party at said substation for refunding the deposited coin, and means to prevent the refund of said coin while said receiver is off its hook.

6. In a telephone system, a telephone line, a substation therefor including a receiver, coin receiving mechanism, a coin magnet and a rectifier, a source of current, means controlled by said mechanism when a coin is deposited for connecting the magnet and rectifier in circuit with said source of current, means for reversing the current source when the called party answers for operating said magnet to collect the coin, a Second magnet at said substation energized over said line to prevent the refund of the coin, and means controlled by said receiver for deenergizing said last mentioned magnet to permit refund.

'7. The combination in a telephone system of a coin controlled substation free from all battery and ground connections thereat, a dial at the substation for sending impulses, a magnet for controlling the disposition of a deposited coin, and a circuit for transmitting the impulses from said dial and for transmitting current to operate said magnet.

8. The combination in a telephone system of a coin controlled substation free from all battery and ground connections thereat, a dial at the substation for sending impulses, coin operated mechanism for rendering said dial effective, and

a magnet at the substation for controlling the disposition of a deposited coin.

9. The combination in a telephone system of a coin substation free from all battery and ground connections thereat, coin disposal mechanism at said substation, and a non-polarized magnet at said substation for actuating said mechanism to dispose of a deposited coin.

10. In combination, a telephone substation including a dial, mechanism for the deposit of coins, and a coin collect magnet, a telephone line, means controlled by the deposit of a coin for connecting said magnet across the conductors of said line, means for including said dial in eries with the line conductors for sending impulses over the line loop, and means including a source of current connected to the line for producing the dial impulses and also serving to operate said magnet to dispose of a deposited com.

11. The combination in a telephone system of a line having a coin operated substation, a coin disposal mechanism, a dial having impulse contacts for transmitting designation impulses over the two conductors of said line in series, a magnet for actuating said mechanism to dispose of a deposited coin, means operated by said mechanism in response to the deposit of the coin for connecting said magnet to the conductors of said line and for rendering the impulse contacts of said dial eifective, and a circuit including the two conductors of said line in series for energizing said magnet to dispose of the deposited coin.

12. The combination in a telephone system of a line having a coin operated substation, a coin disposal mechanism at said substation, a dial having impulse contacts for transmitting designation impulses over the two conductors of said line in series, a magnet for actuating said mechanism to dispose of a deposited coin, means controlled by said mechanism in response to the deposit of a coin for rendering the impulse contacts of said dial eiiective to transmit impulses, means controlled by said dial when positioned for a particular designation for rendering eifective said impulse contacts, and a circuit including the two conductors of said line for operating said magnet to dispose of a deposited coin.

13. The combination in a telephone system of a line having a coin controlled substation, a coin disposal mechanism at said substation, a dial having impulse contacts for transmitting designation impulses over the conductors of said line, circuit means for rendering said impulse contacts ineffective, means controlled by said mechanism in response to the deposit of a coin for rendering said impulse contacts effective to transmit impulses, means controlled by the setting of said dial for a particular designation for rendering said impulse contacts efiective, and means controlled over the conductors of said line for actuating said mechanism to dispose of the deposited coin.

14. The combination in a telephone system of a line having a coin controlled sub-station, automatic switches at the central oflice forextending said line, coin disposal mechanism at said substation, a dial having impulse contacts for transmitting impulses over the conductors of said line to operate said switches, circuit means for rendering said impulse contacts normally ineffective to transmit impulses, means at the substation for closing a signaling circuit including the conductors of said line without rendering said impulse contacts effective, means controlled by said coin disposal mechanism responsive to the deposit of a coin for rendering said impulse contacts effective, means responsive to the setting of said dial for a particular designation for rendering said impulse contacts effective independently of said coin disposal mechanism, and means controlled over the conductors of said line for operating said coin disposal mechanism to dispose of a deposited coin.

15. The combination in a telephone system of a line having a coin controlled substation, a coin mechanism, an impulse transmitter having impulse contacts and means for operating said contacts to send impulses representing a plurality of designations, means controlled by said mechanism in response to the deposit of a coin for rendering said impulse contacts effective when the transmitter is operated in accordance with certain designations, and means for rendering said impulse contacts effective Without the deposit of a coin in said mechanism when the transmitter is operated in accordance with a particular designation.

16. The combination in a telephone system of a line having a coin controlled substation, a coin disposal mechanism, impulse contacts for transmitting series of impulses representing diiierent designations, a dial adjustable to a plurality of designation positons for operating said contacts, means controlled by said coin disposal mechanism for rendering said contacts effective to transmit impulses when the dial is adjusted to certain of said positions, and means controlled by the dial when adjusted to a particular position for rendering said impulse contacts effective independently of the coin mechanism.

17. The combination in a telephone system of a line having a coin controlled substation, a coin disposal mechanism, impulse contacts for transmitting series of impulses representing different designations and a dial adjustable to positions corresponding to the different designations for operating said contacts, a circuit normally rendering said impulse contacts ineffective, means controlled by said coin mechanism in response to the deposit of a coin for opening said circuit to render said impulse contacts efiective to transmit certain designation impulses under the control of said dial, and a circuit closed by the setting of said dial in a particular position for rendering said impulse contacts effective independently of said coin disposal mechanism.

SAMUEL B. WILLIAMS. 

